Convert Hectometer to Gigameter
Convert hectometers to gigameters instantly. 1 hectometer = 1e-7 gigameter — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Gigameter to Hectometer converter for the reverse conversion.
Units explained
Hectometer
A hectometer is a metric unit of length equal to one hundred meters (100 m). It is occasionally used in sports, agricultural surveying, and some European real-estate contexts.
The hectometer was defined alongside the meter when France adopted the metric system in 1795, using the SI prefix hecto- (from Greek hekaton, hundred) to denote multiplication by 100.
Hectometers appear in some sports contexts (the 100 m sprint is technically 1 hm), in agriculture (parcel sizes in some European nations), and in atmospheric science. Most contexts now use meters or kilometers instead.
Adopted in 1795 in France; ratified through the Metre Convention of 1875; remains a defined SI prefix unit although rarely used outside specialised contexts.
Gigameter
A gigameter is a metric unit of length equal to one billion meters (1×10⁹ m). It is most often used in astronomy and astrophysics when expressing distances within the inner solar system.
The gigameter uses the SI prefix giga- (from Greek gigas, giant), adopted by the CGPM in 1960 to denote multiplication by one billion (10⁹).
Gigameters are used to express distances such as the Sun's diameter (~1.39 Gm), the Earth–Moon distance (~0.384 Gm), and similar inner-solar-system scales. Astronomical units and light-seconds are also common for these distances.
SI prefix giga- adopted in 1960; the gigameter became standard in astronomy for sub-AU distances by the late 20th century.
Hectometer to Gigameter conversion formula
The relationship between hectometers and gigameters:
To convert hectometers to gigameters, multiply the value in hectometers by 1e-7. To reverse, multiply gigameters by 1e+7.
How to use this converter
Type a value into the calculator. The result in gigameters updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Gigameter to Hectometer converter for the reverse direction.
Step-by-step: convert hectometers to gigameters
- Write down the value in hectometers (hm).
- Multiply that value by the factor 1e-7.
- The product is the equivalent value in gigameters (Gm).
- To reverse, multiply the gigameter value by 1e+7.
Worked examples
Example 1 — Convert 1 hm to Gm:
1 × 1e-7 = 1e-7 Gm
Example 2 — Convert 100 hm to Gm:
100 × 1e-7 = 1e-5 Gm
Hectometer to Gigameter conversion table
Standard reference values for converting hectometers to gigameters:
| Hectometer [hm] | Gigameter [Gm] |
|---|---|
| 0.01 | 1e-9 |
| 0.1 | 1e-8 |
| 1 | 1e-7 |
| 2 | 2e-7 |
| 3 | 3e-7 |
| 4 | 4e-7 |
| 5 | 5e-7 |
| 10 | 1e-6 |
| 20 | 2e-6 |
| 30 | 3e-6 |
| 40 | 4e-6 |
| 50 | 5e-6 |
| 100 | 1e-5 |
| 500 | 5e-5 |
| 1000 | 1e-4 |
Frequently asked questions
How many gigameters is 1 hectometer?
How do I convert hectometers to gigameters?
How do I convert gigameters back to hectometers?
How many gigameters is 100 hectometers?
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Sources & references
Conversion factor (1 hm = 1e-7 Gm) verified against the following authoritative sources:
- BIPM — The International System of Units (SI Brochure 9th ed.)
Official BIPM publication defining the seven SI base units (including the meter) and the rules for their use. The global authority on units of measurement.
- NIST — Guide to the SI
US National Institute of Standards and Technology reference covering the SI base and derived units with definitions and usage rules for US technical practice.
- NIST Special Publication 811 — Guide for the Use of the International System of Units
Detailed NIST guide covering exact conversion factors between SI and US customary units along with formatting and rounding conventions.
- NIST — Refinement of values for the yard and pound (Federal Register 1959)
The treaty (signed by US
- International Hydrographic Organization — Resolution on the Nautical Mile
International authority that standardised the nautical mile at exactly 1852 m in 1929 — the value adopted worldwide for sea and air navigation.